diff --git a/frontend/src/components/admin/account/AccountActionMenu.vue b/frontend/src/components/admin/account/AccountActionMenu.vue
index 14922a37b7..0523dcad02 100644
--- a/frontend/src/components/admin/account/AccountActionMenu.vue
+++ b/frontend/src/components/admin/account/AccountActionMenu.vue
@@ -1,11 +1,12 @@
 <template>
   <Teleport to="body">
-    <div v-if="show && position">
+    <div v-if="show && anchorRect">
       <!-- Backdrop: click anywhere outside to close -->
       <div class="fixed inset-0 z-[9998]" @click="emit('close')"></div>
       <div
-        class="action-menu-content fixed z-[9999] w-52 overflow-hidden rounded-xl bg-white shadow-lg ring-1 ring-black/5 dark:bg-dark-800"
-        :style="{ top: position.top + 'px', left: position.left + 'px' }"
+        ref="menuRef"
+        class="action-menu-content fixed z-[9999] w-52 overflow-y-auto overscroll-contain rounded-xl bg-white shadow-lg ring-1 ring-black/5 dark:bg-dark-800"
+        :style="menuStyle"
         @click.stop
       >
         <div class="py-1">
@@ -62,14 +63,48 @@
 </template>
 
 <script setup lang="ts">
-import { computed, watch, onUnmounted } from 'vue'
+import { computed, ref, watch, onUnmounted } from 'vue'
+import { useResizeObserver, useWindowSize } from '@vueuse/core'
 import { useI18n } from 'vue-i18n'
 import { Icon } from '@/components/icons'
 import type { Account } from '@/types'
 
-const props = defineProps<{ show: boolean; account: Account | null; position: { top: number; left: number } | null }>()
+const props = defineProps<{ show: boolean; account: Account | null; anchorRect: DOMRect | null }>()
 const emit = defineEmits(['close', 'test', 'stats', 'schedule', 'duplicate', 'reauth', 'refresh-token', 'recover-state', 'reset-quota', 'set-privacy', 'create-spark-shadow'])
 const { t } = useI18n()
+const menuRef = ref<HTMLElement | null>(null)
+const { width: viewportWidth, height: viewportHeight } = useWindowSize()
+const viewportPadding = 8
+const menuPosition = ref({ top: viewportPadding, left: viewportPadding })
+const menuStyle = computed(() => ({
+  top: `${menuPosition.value.top}px`,
+  left: `${menuPosition.value.left}px`,
+  maxWidth: `${Math.max(0, viewportWidth.value - viewportPadding * 2)}px`,
+  maxHeight: `${Math.max(0, viewportHeight.value - viewportPadding * 2)}px`
+}))
+
+const updatePosition = () => {
+  if (!menuRef.value || !props.anchorRect) return
+
+  const { width, height } = menuRef.value.getBoundingClientRect()
+  const anchor = props.anchorRect
+  const gap = 4
+  const maxTop = viewportHeight.value - height - viewportPadding
+  const top = anchor.bottom + gap <= maxTop
+    ? anchor.bottom + gap
+    : anchor.top - height - gap
+  const left = viewportWidth.value < 768
+    ? anchor.left + anchor.width / 2 - width / 2
+    : anchor.right - width
+
+  menuPosition.value.top = Math.max(viewportPadding, Math.min(top, maxTop))
+  menuPosition.value.left = Math.max(viewportPadding, Math.min(left, viewportWidth.value - width - viewportPadding))
+}
+
+// Measure after rendering; menu items and translated labels can change its size.
+watch([menuRef, () => props.anchorRect, viewportWidth, viewportHeight], updatePosition, { flush: 'post' })
+useResizeObserver(menuRef, updatePosition)
+
 const canDuplicate = computed(() => {
   if (!props.account || props.account.parent_account_id != null) return false
   return ['apikey', 'upstream', 'bedrock', 'service_account'].includes(props.account.type)
diff --git a/frontend/src/components/admin/account/__tests__/AccountActionMenu.position.spec.ts b/frontend/src/components/admin/account/__tests__/AccountActionMenu.position.spec.ts
new file mode 100644
index 0000000000..59b7bc2763
--- /dev/null
+++ b/frontend/src/components/admin/account/__tests__/AccountActionMenu.position.spec.ts
@@ -0,0 +1,152 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { enableAutoUnmount, flushPromises, mount } from '@vue/test-utils'
+import AccountActionMenu from '../AccountActionMenu.vue'
+import type { Account } from '@/types'
+
+vi.mock('vue-i18n', () => ({
+  useI18n: () => ({ t: (key: string) => key })
+}))
+
+const account = {
+  id: 1,
+  platform: 'openai',
+  type: 'oauth',
+  status: 'active',
+  rate_limit_reset_at: '2099-01-01T00:00:00Z'
+} as Account
+
+let menuHeight: number
+let resizeMenu: ResizeObserverCallback
+
+const getMenu = () => document.body.querySelector<HTMLElement>('.action-menu-content')!
+const getTop = () => Number.parseFloat(getMenu().style.top)
+const getLeft = () => Number.parseFloat(getMenu().style.left)
+
+function setViewport(width: number, height: number) {
+  vi.stubGlobal('innerWidth', width)
+  vi.stubGlobal('innerHeight', height)
+  window.dispatchEvent(new Event('resize'))
+}
+
+async function mountMenu(anchorRect = new DOMRect(950, 720, 32, 24)) {
+  const wrapper = mount(AccountActionMenu, {
+    props: { show: true, account, anchorRect },
+    global: { stubs: { Icon: true } }
+  })
+  await flushPromises()
+  return wrapper
+}
+
+enableAutoUnmount(afterEach)
+
+describe('AccountActionMenu viewport positioning', () => {
+  beforeEach(() => {
+    menuHeight = 305
+    setViewport(1024, 768)
+    vi.spyOn(HTMLElement.prototype, 'getBoundingClientRect').mockImplementation(function (this: HTMLElement) {
+      if (!this.classList.contains('action-menu-content')) return new DOMRect()
+      return new DOMRect(0, 0, Math.min(208, window.innerWidth - 16), Math.min(menuHeight, window.innerHeight - 16))
+    })
+    vi.stubGlobal('ResizeObserver', class {
+      constructor(callback: ResizeObserverCallback) { resizeMenu = callback }
+      observe = vi.fn()
+      disconnect = vi.fn()
+      unobserve = vi.fn()
+    })
+  })
+
+  afterEach(() => {
+    vi.restoreAllMocks()
+    vi.unstubAllGlobals()
+  })
+
+  it('measures a long OAuth menu and opens above the last row', async () => {
+    await mountMenu()
+
+    expect(getTop()).toBe(720 - 305 - 4)
+    expect(getLeft()).toBe(982 - 208)
+    expect(getTop() + menuHeight).toBeLessThanOrEqual(window.innerHeight - 8)
+    expect(getMenu().textContent).toContain('admin.accounts.recoverState')
+  })
+
+  it('opens below the trigger when the complete menu fits', async () => {
+    await mountMenu(new DOMRect(500, 100, 32, 24))
+
+    expect(getTop()).toBe(128)
+    expect(getLeft()).toBe(324)
+  })
+
+  it('centers a mobile menu on its trigger and flips above the last row', async () => {
+    setViewport(390, 600)
+    await mountMenu(new DOMRect(179, 550, 32, 24))
+
+    expect(getTop()).toBe(241)
+    expect(getLeft()).toBe(91)
+  })
+
+  it.each([0, 370])('keeps mobile menus within the horizontal margins at x=%i', async (x) => {
+    setViewport(390, 600)
+    await mountMenu(new DOMRect(x, 100, 24, 24))
+
+    expect(getLeft()).toBeGreaterThanOrEqual(8)
+    expect(getLeft() + 208).toBeLessThanOrEqual(382)
+  })
+
+  it('constrains an oversized menu and preserves the recover-state action', async () => {
+    setViewport(180, 220)
+    const wrapper = await mountMenu(new DOMRect(150, 180, 24, 24))
+
+    expect(getTop()).toBe(8)
+    expect(getLeft()).toBe(8)
+    expect(getMenu().style.maxHeight).toBe('204px')
+    expect(getMenu().style.maxWidth).toBe('164px')
+    expect(getMenu().classList.contains('overflow-y-auto')).toBe(true)
+    expect(getMenu().classList.contains('overscroll-contain')).toBe(true)
+
+    const recover = Array.from(getMenu().querySelectorAll('button'))
+      .find(button => button.textContent?.includes('admin.accounts.recoverState'))!
+    recover.click()
+    expect(wrapper.emitted('recover-state')).toEqual([[account]])
+    expect(wrapper.emitted('close')).toHaveLength(1)
+  })
+
+  it('repositions when menu content grows', async () => {
+    await mountMenu()
+    menuHeight = 420
+    resizeMenu([], {} as ResizeObserver)
+    await flushPromises()
+
+    expect(getTop()).toBe(296)
+  })
+
+  it('repositions and updates size limits after a viewport resize', async () => {
+    await mountMenu()
+    setViewport(320, 240)
+    await flushPromises()
+
+    expect(getTop()).toBe(8)
+    expect(getLeft()).toBe(104)
+    expect(getMenu().style.maxHeight).toBe('224px')
+    expect(getMenu().style.maxWidth).toBe('304px')
+  })
+
+  it('remeasures after reopening on another row', async () => {
+    const wrapper = await mountMenu()
+    await wrapper.setProps({ show: false })
+    expect(getMenu()).toBeNull()
+    await wrapper.setProps({ show: true, anchorRect: new DOMRect(400, 100, 32, 24) })
+    await flushPromises()
+
+    expect(getTop()).toBe(128)
+    expect(getLeft()).toBe(224)
+  })
+
+  it('still closes on Escape and backdrop clicks', async () => {
+    const wrapper = await mountMenu()
+    window.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape' }))
+    const backdrop = getMenu().previousElementSibling as HTMLElement
+    backdrop.click()
+
+    expect(wrapper.emitted('close')).toHaveLength(2)
+  })
+})
diff --git a/frontend/src/components/admin/account/__tests__/AccountActionMenu.spark_shadow.spec.ts b/frontend/src/components/admin/account/__tests__/AccountActionMenu.spark_shadow.spec.ts
index 4de0008f96..f28c23e326 100644
--- a/frontend/src/components/admin/account/__tests__/AccountActionMenu.spark_shadow.spec.ts
+++ b/frontend/src/components/admin/account/__tests__/AccountActionMenu.spark_shadow.spec.ts
@@ -42,7 +42,7 @@ function makeAccount(overrides: Partial<Account>): Account {
   }
 }
 
-const position = { top: 100, left: 100 }
+const anchorRect = new DOMRect(100, 100, 24, 24)
 
 // AccountActionMenu uses <Teleport to="body">; content is rendered in document.body, not in wrapper.
 const getBodyText = () => document.body.textContent ?? ''
@@ -52,7 +52,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('普通账号显示「复制账号」按钮', () => {
     const account = makeAccount({ platform: 'anthropic', type: 'apikey', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).toContain('admin.accounts.duplicateAccount')
@@ -62,7 +62,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('影子账号隐藏「复制账号」按钮', () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: 42 })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).not.toContain('admin.accounts.duplicateAccount')
@@ -72,7 +72,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it.each(['oauth', 'setup-token'] as const)('%s 账号隐藏「复制账号」按钮，避免共享可轮换令牌', (type) => {
     const account = makeAccount({ platform: 'openai', type, parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).not.toContain('admin.accounts.duplicateAccount')
@@ -82,7 +82,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('点击「复制账号」触发 duplicate 事件并携带 account', async () => {
     const account = makeAccount({ platform: 'anthropic', type: 'apikey', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
 
@@ -101,7 +101,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('OpenAI OAuth 母账号（无 parent_account_id）显示「创建 spark 影子」按钮', () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).toContain('admin.accounts.createSparkShadow')
@@ -111,7 +111,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('影子账号（parent_account_id 非 null）隐藏「创建 spark 影子」按钮', () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: 42 })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).not.toContain('admin.accounts.createSparkShadow')
@@ -121,7 +121,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('非 OpenAI 账号隐藏「创建 spark 影子」按钮', () => {
     const account = makeAccount({ platform: 'antigravity', type: 'oauth', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     expect(getBodyText()).not.toContain('admin.accounts.createSparkShadow')
@@ -131,7 +131,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('影子账号隐藏凭据/隐私类操作(重授权/刷新token/隐私)— 外审 G4', () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: 42 })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     const body = getBodyText()
@@ -144,7 +144,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('普通 OpenAI OAuth 母账号仍显示凭据/隐私类操作', () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
     const body = getBodyText()
@@ -156,7 +156,7 @@ describe('AccountActionMenu — spark shadow 按钮可见性', () => {
   it('点击按钮触发 create-spark-shadow 事件并携带 account', async () => {
     const account = makeAccount({ platform: 'openai', type: 'oauth', parent_account_id: null })
     const wrapper = mount(AccountActionMenu, {
-      props: { show: true, account, position },
+      props: { show: true, account, anchorRect },
       attachTo: document.body,
     })
 
diff --git a/frontend/src/views/admin/AccountsView.vue b/frontend/src/views/admin/AccountsView.vue
index d156b389e9..6cc73880de 100644
--- a/frontend/src/views/admin/AccountsView.vue
+++ b/frontend/src/views/admin/AccountsView.vue
@@ -456,7 +456,7 @@
     <AccountTestModal :show="showTest" :account="testingAcc" @close="closeTestModal" />
     <AccountStatsModal :show="showStats" :account="statsAcc" @close="closeStatsModal" />
     <ScheduledTestsPanel :show="showSchedulePanel" :account-id="scheduleAcc?.id ?? null" :model-options="scheduleModelOptions" @close="closeSchedulePanel" />
-    <AccountActionMenu :show="menu.show" :account="menu.acc" :position="menu.pos" @close="menu.show = false" @test="handleTest" @stats="handleViewStats" @schedule="handleSchedule" @duplicate="handleDuplicateAccount" @reauth="handleReAuth" @refresh-token="handleRefresh" @recover-state="handleRecoverState" @reset-quota="handleResetQuota" @set-privacy="handleSetPrivacy" @create-spark-shadow="handleCreateSparkShadow" />
+    <AccountActionMenu :show="menu.show" :account="menu.acc" :anchor-rect="menu.anchorRect" @close="menu.show = false" @test="handleTest" @stats="handleViewStats" @schedule="handleSchedule" @duplicate="handleDuplicateAccount" @reauth="handleReAuth" @refresh-token="handleRefresh" @recover-state="handleRecoverState" @reset-quota="handleResetQuota" @set-privacy="handleSetPrivacy" @create-spark-shadow="handleCreateSparkShadow" />
     <SyncFromCrsModal :show="showSync" @close="showSync = false" @synced="reload" />
     <ImportDataModal :show="showImportData" @close="showImportData = false" @imported="handleDataImported" />
     <BulkEditAccountModal
@@ -614,7 +614,7 @@ const showSchedulePanel = ref(false)
 const scheduleAcc = ref<Account | null>(null)
 const scheduleModelOptions = ref<SelectOption[]>([])
 const togglingSchedulable = ref<number | null>(null)
-const menu = reactive<{show:boolean, acc:Account|null, pos:{top:number, left:number}|null}>({ show: false, acc: null, pos: null })
+const menu = reactive<{show:boolean, acc:Account|null, anchorRect:DOMRect|null}>({ show: false, acc: null, anchorRect: null })
 const exportingData = ref(false)
 const probingUpstreamBilling = reactive(new Set<number>())
 const upstreamBillingProbeGloballyEnabled = ref<boolean | undefined>(undefined)
@@ -1844,53 +1844,8 @@ const handleEdit = async (a: AccountListItem) => {
 }
 const openMenu = (a: Account, e: MouseEvent) => {
   menu.acc = a
-
   const target = e.currentTarget as HTMLElement
-  if (target) {
-    const rect = target.getBoundingClientRect()
-    const menuWidth = 200
-    const menuHeight = 240
-    const padding = 8
-    const viewportWidth = window.innerWidth
-    const viewportHeight = window.innerHeight
-
-    let left: number
-    let top: number
-
-    if (viewportWidth < 768) {
-      // 居中显示,水平位置
-      left = Math.max(padding, Math.min(
-        rect.left + rect.width / 2 - menuWidth / 2,
-        viewportWidth - menuWidth - padding
-      ))
-
-      // 优先显示在按钮下方
-      top = rect.bottom + 4
-
-      // 如果下方空间不够,显示在上方
-      if (top + menuHeight > viewportHeight - padding) {
-        top = rect.top - menuHeight - 4
-        // 如果上方也不够,就贴在视口顶部
-        if (top < padding) {
-          top = padding
-        }
-      }
-    } else {
-      left = Math.max(padding, Math.min(
-        e.clientX - menuWidth,
-        viewportWidth - menuWidth - padding
-      ))
-      top = e.clientY
-      if (top + menuHeight > viewportHeight - padding) {
-        top = viewportHeight - menuHeight - padding
-      }
-    }
-
-    menu.pos = { top, left }
-  } else {
-    menu.pos = { top: e.clientY, left: e.clientX - 200 }
-  }
-
+  menu.anchorRect = target.getBoundingClientRect()
   menu.show = true
 }
 const toggleSelectAllVisible = (event: Event) => {
@@ -2538,7 +2493,8 @@ const proxyExpiryText = (p: AccountProxy): string => {
 }
 
 // 表格滚动时关闭行操作菜单，并让顶部工具菜单继续贴紧触发按钮。
-const handleScroll = () => {
+const handleScroll = (event: Event) => {
+  if (event.target instanceof Element && event.target.closest('.action-menu-content')) return
   menu.show = false
   if (showAccountToolsDropdown.value) updateAccountToolsDropdownPosition()
 }
diff --git a/frontend/src/views/admin/__tests__/AccountsView.lite.spec.ts b/frontend/src/views/admin/__tests__/AccountsView.lite.spec.ts
index 8ad9b681f6..86d29caad1 100644
--- a/frontend/src/views/admin/__tests__/AccountsView.lite.spec.ts
+++ b/frontend/src/views/admin/__tests__/AccountsView.lite.spec.ts
@@ -1,5 +1,5 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
-import { flushPromises, mount } from '@vue/test-utils'
+import { DOMWrapper, flushPromises, mount } from '@vue/test-utils'
 import { defineComponent } from 'vue'
 
 import AccountsView from '../AccountsView.vue'
@@ -88,8 +88,9 @@ const AccountStatsModalStub = defineComponent({
   template: '<div data-test="stats-account">{{ show ? account?.name : "" }}</div>'
 })
 
-function mountView() {
+function mountView(stubActionMenu = true) {
   return mount(AccountsView, {
+    attachTo: document.body,
     global: {
       stubs: {
         AppLayout: { template: '<div><slot /></div>' },
@@ -100,7 +101,7 @@ function mountView() {
         AccountBulkActionsBar: true,
         Pagination: true,
         ConfirmDialog: true,
-        AccountActionMenu: true,
+        AccountActionMenu: stubActionMenu,
         ImportDataModal: true,
         ReAuthAccountModal: true,
         AccountTestModal: AccountTestModalStub,
@@ -122,7 +123,7 @@ function mountView() {
         UpstreamBillingRateCell: true,
         HelpTooltip: true,
         Icon: true,
-        Teleport: true
+        Teleport: stubActionMenu
       }
     }
   })
@@ -189,6 +190,27 @@ describe('admin AccountsView lite account list', () => {
     wrapper.unmount()
   })
 
+  it('keeps the action menu open during internal scrolling but closes it on table scrolling', async () => {
+    const wrapper = mountView(false)
+    await flushPromises()
+
+    const trigger = wrapper.findAll('button').find(button => button.text() === 'common.more')!
+    await trigger.trigger('click')
+    const menu = new DOMWrapper(document.body.querySelector('.action-menu-content')!)
+    menu.element.dispatchEvent(new Event('scroll'))
+    await flushPromises()
+    expect(wrapper.findComponent(AccountActionMenu).props('show')).toBe(true)
+
+    menu.get('button').element.dispatchEvent(new Event('scroll'))
+    await flushPromises()
+    expect(wrapper.findComponent(AccountActionMenu).props('show')).toBe(true)
+
+    wrapper.getComponent(DataTableStub).element.dispatchEvent(new Event('scroll'))
+    await flushPromises()
+    expect(wrapper.findComponent(AccountActionMenu).props('show')).toBe(false)
+    wrapper.unmount()
+  })
+
   it('keeps lite=1 on automatic ETag refreshes', async () => {
     vi.useFakeTimers()
     vi.spyOn(document, 'hidden', 'get').mockReturnValue(false)